Add some closureised JS bindings for DevTools for use by headless embedder

headless/test/bindings_test.js

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+goog.module('chromium.BindingsTest');
+// Needed to let C++ invoke the test.
+goog.module.declareLegacyNamespace();
+
+const Connection = goog.require('chromium.DevTools.Connection');
+const DOM = goog.require('chromium.DevTools.DOM');
+const Runtime = goog.require('chromium.DevTools.Runtime');
+
+/**
+ * A trivial test which is invoked from C++ by HeadlessJsBindingsTest.
+ */
+class BindingsTest {
+  constructor() {}
+
+  /**
+   * Evaluates 1+1 and returns the result over the chromium.DevTools.Connection.
+   */
+  evalOneAddOne() {
+    let connection = new Connection(window.TabSocket);
+    let runtime = new Runtime(connection);
+    runtime.Evaluate({'expression': '1+1'}).then(function(message) {
+      connection.sendDevToolsMessage(
+          '__Result',
+          {'result': JSON.stringify(message.result.value)});
+    });
+  }
+
+  /**
+   * Evaluates 1+1 and returns the result over the chromium.DevTools.Connection.
+   */
+  listenForChildNodeCountUpdated() {
+    let connection = new Connection(window.TabSocket);
+    let dom = new DOM(connection);
+    dom.OnChildNodeCountUpdated(function(params) {
+      connection.sendDevToolsMessage('__Result',
+                                     {'result': JSON.stringify(params)});
+    });
+    dom.Enable().then(function() {
+      return dom.GetDocument({});
+    }).then(function() {
+      // Create a new div which should trigger the event.
+      let div = document.createElement('div');
+      document.body.appendChild(div);
+    });
+  }
+}
+
+exports = BindingsTest;